Acoustic properties of Norway spruce wood modified with staining fungus (Sydowia polyspora)

Abstract

Effects of biological modification of Norway spruce wood with the wood-staining fungus Sydowia polyspora were evaluated relative to select physical and acoustical characteristics (PACHs), including the density (ρ), dynamic modulus of elasticity along the wood grain (EL), specific modulus (Esp), speed of sound along the wood grain (cL), resonant frequency (fr), acoustic constant (A), logarithmic decrement (ϑ), loss coefficient (η), acoustic conversion efficiency (ACE), sound quality factor (Q), and sound timbre. Incubation of the Norway spruce samples in S. polyspora lasted 12 w, 20 w, and 24 w. The results showed that the incubation time of spruce wood in S. polyspora did not have a statistically significant impact on most of the PACHs (ρ, EL, cL, fr, and A). However, biological modification of the spruce wood with S. polyspora had significant effects on the ϑ, η, and ACE. Treatment of the spruce wood with S. polyspora also changed the sound timbre, but the effects varied for each frequency.

Aging of Wood for Musical Instruments: Analysis of Changes in Color, Surface Morphology, Chemical, and Physical-Acoustical Properties during UV and Thermal Exposure

“…From a qualitative point of view, it can be concluded that the UV and thermal treatment led to an improvement in the acoustic and elastic parameters of the wood selected for musical instruments, as characterized by the relatively low thickness (maximum 4 mm) studied in this paper. In agreement with the above findings, the literature data [17,24,25,28,[48][49][50][51][52][53] confirm that the ultrasound velocity and dynamic elastic modulus of the aged wood shift to higher values when compared to that of recently produced wood.…”

Sustainability in wood materials science: an opinion about current material development techniques and the end of lifetime perspectives

“…To do so, various modification techniques are available. According to the types of properties required for the finished wood product, the natural wood scaffold will undergo a modification triggered by mechanical, [20] thermal, [21] chemical, [22] or biological [23] methods (or a combination of those). The goal of these modifications is always to alter the structure and/or the composition of wood, to obtain enhanced performances or new characteristics for novel applications.…”

Avaliação das propriedades acústicas de mogno africano (Khaya ivorensis) submetido a tratamento térmico em estufa e autoclave

“…O tratamento térmico é realizado quando se deseja alterar a estrutura física e química da madeira com a intenção de provocar degradação ou rearranjo dos seus principais constituintes, modificando dessa forma algumas de suas propriedades físicas e mecânicas. Da mesma forma, modificações da madeira utilizando processos de acetilação; tratamentos com melamina e fenol formaldeído [1,2]; e modificação biológica com fungos que mancham ou destroem a madeira [1,3] podem ser usados para modificar as propriedades relevantes.…”